To sustain a medical malpractice claim of negligence, a plaintiff must prove by a preponderence of evidence: (1) a duty by the physician to act according to a certain standard; (2) a breach of the applicable standard of care; (3) an injury; (4) a causal connection between the breach of care and the injury. Schorlemer v. Reyes, 974 S.W.2d 141, 147 (Tex.App.-San Antonio 1998, writ denied); see also Mathis v. Bocell, 982 S.W.2d 52, 56 (Tex. App.-Houston [1st Dist.] 1998, no writ). A hospital is not ordinarily liable for the negligence of a physician who is an independent contractor. Baptist Mem'l Hosp. Sys. v. Sampson, 969 S.W.2d 945, 948 (Tex. 1998). However "a hospital may be vicariously liable for the medical malpractice of independent contractor physicians when plaintiffs can establish the elements of ostensible agency." Id. To establish a hospital's liability for an independent contractor's medical malpractice based on ostensible agency, a plaintiff must show that: (1) he or she had a reasonable belief that the physician was the agent or employee of the hospital; (2) such belief was generated by the hospital affirmatively holding out the physician as its agent or employee or knowingly permitting the physician to hold herself out as the hospital's agent or employee; (3) he or she justifiably relied on the representation of authority. Id. at 949.